Just wanting to know if I can build a load bearing beam out of three 11-7/8" 2x12's for a span of 10 feet. with a nail pattern of 4 nails on each side at every 12". Would this pass inspection?

What u have listed is more then needed for a 10 foot span if a 2 story house.

In my area 2-2x12 would be approved.

Chuck

Depends upon where this beam will be located and what loads it will be expected to support.

No one can answer until you provide more specific load information and where the beam will be located.